A chronic autoimmune liver disease characterized by progressive destruction of small intrahepatic bile ducts, leading to cholestasis, fibrosis, and eventually cirrhosis. Highly associated with anti-mitochondrial antibodies (AMA) targeting pyruvate dehydrogenase complex.
name: Primary Biliary Cholangitis
creation_date: '2025-12-19T01:12:52Z'
updated_date: '2026-02-17T21:53:14Z'
category: Autoimmune
parents:
- Autoimmune Disease
- Liver Disease
disease_term:
preferred_term: Primary Biliary Cholangitis
term:
id: MONDO:0005388
label: primary biliary cholangitis
description: >-
A chronic autoimmune liver disease characterized by progressive destruction
of small intrahepatic bile ducts, leading to cholestasis, fibrosis, and
eventually cirrhosis. Highly associated with anti-mitochondrial antibodies
(AMA) targeting pyruvate dehydrogenase complex.
pathophysiology:
- name: Anti-Mitochondrial Antibody Response
description: >-
Autoantibodies against the E2 subunit of pyruvate dehydrogenase complex
(PDC-E2) are highly specific for PBC. These antibodies may directly
contribute to biliary epithelial cell damage through immune complex
formation and complement activation.
biological_processes:
- preferred_term: Immunoglobulin Production
term:
id: GO:0002377
label: immunoglobulin production
evidence:
- reference: PMID:26953925
supports: PARTIAL
snippet: >-
Primary biliary cholangitis (PBC) is an autoimmune hepatobiliary disease
characterized by immune mediated destruction of the intrahepatic small bile
ducts and the presence of antimitochondrial antibodies (AMAs). The mitochondrial
autoantigens have been identified as the E2 subunits of the 2-oxo-acid
dehydrogenase complex, including the E2 subunits of pyruvate dehydrogenase,
branched-chain 2-oxo acid dehydrogenase complex, oxoglutarate dehydrogenase
complex, E3 binding protein and PDC E1 alpha subunit.
explanation: >-
This paper confirms that AMAs targeting PDC-E2 and related E2 subunits are
characteristic of PBC and are associated with immune-mediated bile duct destruction.
- reference: PMID:39329760
supports: PARTIAL
snippet: >-
Although the pathogenesis of the disease is multifactorial, there is a consensus
that individuals with a genetic predisposition develop the disease in the
presence of specific environmental triggers. A dysbiosis of intestinal
microbiota is increasingly considered among the potential pathogenic factors.
explanation: >-
This review highlights the multifactorial pathogenesis of PBC, including
genetic predisposition and environmental triggers that lead to AMA production
and disease development.
- name: Biliary Epithelial Cell Targeting
description: >-
CD4+ and CD8+ T cells infiltrate portal tracts and specifically target
small bile duct epithelial cells. Aberrant PDC-E2 expression on apoptotic
cholangiocytes may initiate the autoimmune response.
cell_types:
- preferred_term: Cholangiocyte
term:
id: CL:0000182
label: hepatocyte
- preferred_term: CD8+ T Cell
term:
id: CL:0000625
label: CD8-positive, alpha-beta T cell
biological_processes:
- preferred_term: T Cell Cytotoxicity
term:
id: GO:0001913
label: T cell mediated cytotoxicity
evidence:
- reference: PMID:24556277
supports: PARTIAL
snippet: >-
In vitro cholangiocyte cytotoxicity assays demonstrated significantly
increased numbers of cytotoxic hepatic dnTGFβRII KLRG1(+) CD8 cells
compared to B6. Protection from disease by B6 Tregs was associated with
elimination of hepatic dnTGFβRII CD8 mediated cholangiocyte cytotoxicity.
These results emphasize that autoimmune cholangitis requires defects in
both the T effector and regulatory compartments.
explanation: >-
This study demonstrates that cytotoxic CD8+ T cells directly target and
destroy cholangiocytes in experimental PBC, supporting the role of T cell-
mediated cytotoxicity in bile duct epithelial cell destruction.
- reference: PMID:39329760
supports: SUPPORT
snippet: >-
Cholangiocytes, the epithelial cells lining the bile ducts, are the main
target of a dysregulated immune response, and cholangiocytes senescence
has been recognized as a driving mechanism, leading to impaired bile duct
function, in disease progression.
explanation: >-
This review confirms that cholangiocytes are the primary cellular targets
of immune attack in PBC, with senescent cholangiocytes driving disease
progression through impaired bile duct function.
- name: Progressive Ductopenia and Cholestasis
description: >-
Destruction of bile ducts leads to ductopenia, impaired bile flow, and
accumulation of toxic bile acids. Retained bile acids cause further
hepatocyte damage and promote fibrosis.
biological_processes:
- preferred_term: Bile Acid Metabolic Process
term:
id: GO:0008206
label: bile acid metabolic process
evidence:
- reference: PMID:37047635
supports: PARTIAL
snippet: >-
In recent years, several studies have shown that, in case of a change in
gut bacterial homeostasis or impairment of intestinal barrier functions,
cholangiocytes, which are the epithelial cells lining the bile ducts,
activate innate immune responses against gut-derived microorganisms or
bacterial products that reach the liver via enterohepatic circulation.
Intestinal dysbiosis or impaired intestinal barrier functions cause
cholangiocytes to be exposed to an increasing amount of microorganisms
that can reactivate inflammatory responses, thus inducing the onset of
liver fibrosis.
explanation: >-
This review demonstrates that cholangiocyte injury and bile duct destruction
in PBC are promoted by gut-derived bacterial products reaching the liver,
which trigger inflammatory responses that induce liver fibrosis and progressive
disease.
- reference: PMID:39329760
supports: PARTIAL
snippet: >-
Bile acids are also recognized as playing an important role, both in disease
development and therapy. Thus, while bile acid-based therapies, specifically
ursodeoxycholic acid and obeticholic acid, have been the cornerstone of
therapy in PBC, novel therapeutic approaches have been developed in recent years.
explanation: >-
This review highlights the central role of bile acids in PBC pathogenesis,
noting that bile acid accumulation contributes to disease progression and
that bile acid modulation is a key therapeutic strategy.
phenotypes:
- name: Pruritus
category: Dermatological
frequency: VERY_FREQUENT
phenotype_term:
preferred_term: Pruritus
term:
id: HP:0000989
label: Pruritus
notes: Often the presenting symptom
evidence:
- reference: PMID:35704252
supports: PARTIAL
snippet: >-
Pruritus was reported in 170 patients (81%), with those reporting clinically
significant pruritus (30%) scoring worse across each domain of the PBC-40 and
5-D itch, more frequently having cirrhosis, and having significantly greater
levels of fatigue.
explanation: >-
This real-world cohort study demonstrates that pruritus is highly prevalent
in PBC (81%), with clinically significant pruritus associated with worse
quality of life, more advanced disease, and greater fatigue.
- name: Fatigue
category: Systemic
frequency: VERY_FREQUENT
phenotype_term:
preferred_term: Fatigue
term:
id: HP:0012378
label: Fatigue
evidence:
- reference: PMID:35704252
supports: PARTIAL
snippet: >-
Pruritus was reported in 170 patients (81%), with those reporting clinically
significant pruritus (30%) scoring worse across each domain of the PBC-40 and
5-D itch, more frequently having cirrhosis, and having significantly greater
levels of fatigue.
explanation: >-
This study shows that fatigue is significantly elevated in PBC patients,
particularly in those with clinically significant pruritus.
- name: Jaundice
category: Hepatic
frequency: FREQUENT
phenotype_term:
preferred_term: Jaundice
term:
id: HP:0000952
label: Jaundice
notes: Indicates advanced disease
- name: Hepatomegaly
category: Hepatic
frequency: FREQUENT
phenotype_term:
preferred_term: Hepatomegaly
term:
id: HP:0002240
label: Hepatomegaly
biochemical:
- name: Anti-Mitochondrial Antibodies (AMA)
presence: Elevated
context: Present in 95% of patients, highly specific
evidence:
- reference: PMID:26953925
supports: SUPPORT
snippet: >-
Primary biliary cholangitis (PBC) is an autoimmune hepatobiliary disease
characterized by immune mediated destruction of the intrahepatic small bile
ducts and the presence of antimitochondrial antibodies (AMAs).
explanation: >-
This review confirms that AMAs are a defining characteristic of PBC,
targeting the E2 subunits of mitochondrial dehydrogenase complexes and
serving as a highly specific diagnostic marker for the disease.
- name: Alkaline Phosphatase
presence: Elevated
context: Cholestatic pattern
- name: IgM
presence: Elevated
context: Characteristic finding
- name: Anti-sp100 Antibodies
presence: Variable
context: PBC-specific ANA
genetic:
- name: HLA-DRB1*08
association: Risk Factor
- name: IL12A
association: Risk Factor
- name: IL12RB2
association: Risk Factor
treatments:
- name: Ursodeoxycholic Acid (UDCA)
description: First-line therapy, improves biochemistry and transplant-free
survival.
- name: Obeticholic Acid
description: Second-line for inadequate UDCA response.
- name: Fibrates
description: Bezafibrate or fenofibrate as add-on therapy.
- name: Liver Transplantation
description: For end-stage disease.
classifications:
harrisons_chapter:
- classification_value: liver disorder
- classification_value: autoimmune disease
references:
- reference: DOI:10.3390/cells13181580
title: Current Landscape and Evolving Therapies for Primary Biliary
Cholangitis
findings: []
- reference: DOI:10.3390/genes14020405
title: 'The Genetics of Primary Biliary Cholangitis: A GWAS and Post-GWAS Update'
findings: []
- reference: DOI:10.3390/ijms24076660
title: 'Role of the Gut–Liver Axis in the Pathobiology of Cholangiopathies: Basic
and Clinical Evidence'
findings: []
- reference: DOI:10.3390/ijms26167905
title: 'Primary Biliary Cholangitis: Immunopathogenesis and the Role of Bile Acid
Metabolism in Disease Progression'
findings: []
- reference: DOI:10.3748/wjg.v29.i37.5292
title: New insights into the pathogenesis of primary biliary cholangitis
asymptomatic stage
findings: []